In addition to motor vehicle transmission designs, by means of which the ratio between the transmission input and the transmission output can be varied continuously, those also exist, e.g., by means of which the ratio discussed can be changed in steps.
The classic manual transmission, which has a number of gear sets for formation of ratio steps and/or gears, is an example of a stepped motor vehicle transmission design, in which the drive forces and/or energy required for gear change are applied completely by the driver of the motor vehicle.
In addition, e.g., (stepped) motor vehicle transmission designs are known that have a number of gear sets for forming ratio steps and/or gears, in which the drive forces and/or energy required for gear change are not applied completely by the driver of the motor vehicle. Designs of this type can also be designated as transmission designs with outside power support. Transmission designs frequently have an electromechanical actuator. By means of this actuator that forms the so-called external gear shift and/or is a component of such, a so-called inner gear shift can be actuated. In this case, the inner gear shift has a number of mechanisms and/or final output mechanisms. In this case, each of these final output mechanisms—usually one or two—is assigned to predetermined gears of the transmission that can be engaged and or disengaged by means of the associated final output mechanism, which to do this is correspondingly actuated by means of the gear actuator. Each of these final output mechanisms has a shift rail, shift fork or the like that is provided with an engagement zone, in which the actuator can engage for actuation. This engagement zone is generally formed of at least one shift jaw.
In addition, designs of the type mentioned above are known, in which the actuator has at least two electric motors. One electric motor that is also designated as selector motor is used to generate selecting movement and a second electric motor, also designated as shifting motor is used to generate shifting movement. It is also known that the selector motor is coupled with a central gear-shift shaft in such a way that it can move axially in its longitudinal direction for selection and that the shifting motor is coupled with this central gear-shift shaft in such a way that it can drive in rotation around its longitudinal axis for shifting. A shift finger or the like is provided on the gear-shift shaft that is moved with the gear-shift shaft and can act on a respective final output mechanism and/or shift rail during a shifting movement, and namely generally by way of their and/or its shift jaw.
A design of the previously mentioned type is known to be used, e.g., in automated manual transmissions (ASG).
In transmissions that have two drive train branches shifted in parallel and/or two dividing gears shifted in parallel, like, e.g., double-clutch transmission (DKG) and/or parallel transmission (PSG), known actuators with electric motors are also used. Since the goal of this type of transmissions is generally changing the gears without interruption in tensile force, in this type of transmissions in the scope of gear change processes by means of clutches or the like, there is a change between the dividing gears, whereby first a torque is transferred over a gear of one dividing gear, then at the same time a torque is transferred over both dividing gears, and after that, torque is only transferred over one gear of the other dividing gear. If both dividing gears each have several gears, the target gear must be engaged in the other dividing gear—if it is not already engaged—before the gear is disengaged in a dividing gear. In particular, in view of this, it has become known that in this type of transmission, actuators are used that have a selector motor and a shifting motor for each of the two dividing gears, i.e. a total of four electric motors.
In conventionally designed stepped motor vehicle transmission designs of the type named above—starting from the old gear—the following three steps occur in sequence over time: “disengagement of the old gear”—“selection”—“engagement of the target gear.”
Besides that, the applicant has developed a motor vehicle transmission design, in which the selecting and/or selecting movement can occur before the disengagement of the old gear and/or a motor vehicle gear actuator that uses only one electric motor, which supplies the drive movements both for selecting and also the drive movements for shifting and thus can also be designated as a single-motor gear actuator.
In such designs, it is provided, e.g., that engagement geometries and/or a main actuating element and/or a shift finger is essentially only responsible for the engagement of gears and additional geometries take on the function of the disengagement of gears. In this case especially, disengagement geometries and/or so-called auxiliary actuating elements are used for the disengagement function. In this case, it can be provided, e.g., that the additional geometries, on one hand are located, e.g., on a central gear-shift shaft and on the other, on shift jaws that are provided on the named mechanisms and/or final output mechanisms and/or shift forks or shift rails or the like, but which can also be designed differently.
In most cases, disengagement geometries act in the gates in which the shift finger is not active. In this case it can be provided that a fixed allocation between shift finger and disengagement geometry thereby simultaneously represents an active gear lock. Design implementations of this solution are thus also designated as “active-interlock.”
In such an “active-interlock,” it is generally provided that the main actuating element and/or the shift finger can also be moved into a central and/or neutral position without disengaging the gear. In this case, the selecting movement is possible before the gear is disengaged.
Examples of this type of design with active-interlock and/or of single-motor gear actuators are explained, e.g. in DE 102 06 561 A1 by the applicant.
The invention is based on the goal of producing a simply designed motor vehicle gear actuator, by means of which the gears of a motor vehicle transmission can be engaged and disengaged with operational safety.